Hurricane Irene, which satellite observations reveal is already a third the size of the U.S. East Coast, has already smashed through the Bahamas and is bearing down on Florida. It's expected to slam the southeast for the next few days, working its way up to New York and eventually becoming a torrential rainstorm in the Boston area.

Several states, including North Carolina and Virginia, have already declared a state of emergency and are ordering evacuations. New Jersey could be next. Are you prepared?

Are you planning to travel anywhere to or from the East Coast over the next four days? Bloomberg News says you may want to change your plans — your airline may have already canceled your flight. Many carriers are offering travelers a chance to rebook flights for free.

If you're out of danger, you can watch a mesmerizing, real-time update on the hurricane's progress via the New York Times.